Comment by marcosdumay
4 days ago
Vacuum is only a nearly perfect insulator until a few hundred °C. After that, radiation dominates over every other form of heat exchange, and it stops making any difference.
A couple of meters long steel rod with a dissipator on the end can easily keep electronics at Earth surface temperatures even if you heat the other end to 1000°C.
The air on earth is taking the heat from the dissipators more than blackbody radiation.